And she did it in diva fashion, during a press conference to preview her Super Bowl performance.

She took the stage wearing a super-mini white dress and belted out a powerful — and a cappella — version of the Star Spangled Banner. After repeating the final refrain with vocal fireworks, she took a deep breath, gave thanks and said, "Any questions?"

The implication was simple: For anyone who had any doubts, she can not only sing live but she can do it while performing vocal acrobatics.

Of course the first question from the journalists in the room was what happened at the inauguration.

"I'm a perfectionist," Beyoncé said. She explained that she couldn't practice with the Marine Band and taking the weather and other circumtances into account she did not feel "comfortable taking a risk."

"I decided to sing along with a pre-recorded track."

However, she said, at the Super Bowl half time this Sunday, she will "absolutely be singing live."